A conventional integrated circuit including a diffused resistor in an isolated region is shown in FIG. 1. The transistor 11 is an NPN transistor formed in a first N-type isolated region 12 and a P-type resistor formed in an adjacent N-type isolated region 13 biased to high positive voltage such as V.sub.cc. Another area where a resistor could be formed is in the isolation region. This would have the advantage that the isolation region is already biased to the proper voltage and that less area would be required. However, in conventional integrated circuits, the isolation region is heavily doped P-type material which isolates lightly doped N-regions. The normal resistors are made with a P-type diffusion into the epitaxially doped N-type epitaxial region. The only kind of resistor that can be made in the P-type isolation region is a heavily doped N-type resistor. The problem is that such a resistor will have a very low sheet resistance and a very low breakdown voltage.